Due to us using size_t for the length, the actual value will always be positive.
If, for example, we calculate the length as "0 - 1", we'll get SIZE_T_MAX. What
we can do is check that adding the characters pointer and the length together
doesn't overflow.
And switch the two-argument version of Checked::multiplication_would_overflow()
to use __builtin_mul_overflow_p(). This helps GCC optimize the code better.
There were some ideas about how to use this class but we never actually
started using it, so let's just simplify it and get it ready for use.
The basic idea is: a function returns a Result<ValueType, ErrorType>.
Callers check if the result object is_error(). If so, an ErrorType can
be fetched with the error() getter. Otherwise, a ValueType is fetched
with the value() getter. That's it. :^)
DWARF line number information, if generated, is stored in the
.debug_line section of an object file.
The information is encoded as instructions for a VM that is defined in
the DWARF specification.
By executing these instructions, we can extract the encoded line number
information.
We allow the ref-counting parts of an object to be mutated even when the
object itself is a const.
An important detail is that we allow invoking 'will_be_destroyed' and
'one_ref_left', which are not required to be const qualified, on const
objects.
This is an utility to create a URL from a given string, which may be either a
URL such as http://example.com (which will be used as-is), or a file path such
as /etc/fstab (which will be transformed into file:///etc/fstab).
Since the FlyString deduplication mechanism uses a HashTable, we know
that any StringImpl inside a non-null FlyString will already have its
lazily computed hash.
This turns into much less code in the most common cases, here's why:
The normal Optional usage pattern is something like:
auto foo = get_me_an_optional();
if (foo.has_value())
do_stuff_with(foo.value());
In this typical scenario, we check has_value() before calling value().
Without inlining, value() will double-check has_value() itself and
assert if it fails. Inlining allows the compiler to optimize all of
this away.
Clang keeps whining that NonnullFooPtrs are in "unknown" state and I'm
not sure how to resolve that right now. Disable the checking until we
can figure it out.
Our C++ code generator tools have been relying on host-side dbg() being
forwarded to stdout until now. Now they use out() instead.
Hopefully this will make it easier and more enticing to use streams in
userspace programs as well. :^)
AK::Bitmap is extended with find_next_range_of_unset_bits().
The function is implemented using count_trailing_zeroes_32(), which is
optimized on many platforms, that gives a huge performance boost.
Functions find_longest_range_of_unset_bits() and find_first_fit() are
implemented with find_next_range_of_unset_bits(). According to
benchmarks, they are 60-100% faster.
Same issue here as we had with RefPtr and NonnullRefPtr.
Since we can't make copies of an owning pointer, we don't get quite the
same static_ptr_cast<T> here. Instead I've only added a new templated
version of OwnPtr::release_nonnull() in this patch, to solve the only
issue that popped up.
I'm not sure what the best solution here is, but this works for now.
We were allowing this dangerous kind of thing:
RefPtr<Base> base;
RefPtr<Derived> derived = base;
This patch changes the {Nonnull,}RefPtr constructors so this is no
longer possible.
To downcast one of these pointers, there is now static_ptr_cast<T>:
RefPtr<Derived> derived = static_ptr_cast<Derived>(base);
Fixing this exposed a ton of cowboy-downcasts in various places,
which we're now forced to fix. :^)
